In recent years, attention has been given to a feed system (a noncontact feed system or a wireless charging system) that performs noncontact power supply (electric power transmission) to a CE device (Consumer Electronics Device) such as a portable telephone or a portable music player. This makes it possible to start the charge merely by placing an electronic device (a secondary-side device) on a charging tray (a primary-side device), instead of starting the charge by inserting (connecting) a connector of a power-supply unit such as an AC adapter into the device. In other words, terminal connection between the electronic device and the charging tray become unnecessary.
As a method of thus performing noncontact power supply, an electromagnetic induction method is well known. In recent years, a noncontact feed system using a method called a magnetic resonance method has also been receiving attention. Such noncontact feed systems are disclosed in PTLs 1 to 3, for example.